In silver halide color photographic light-sensitive materials, it is well known that, with an exposed silver halide serving as an oxidizer, an oxidized aromatic primary amine-series color-developing agent and a coupler are reacted to produce a dye, such as indophenol, indoaniline, indamine, azomethine, phenoxazine, and phenazine, to form an image. In this photographic system, the subtractive color process is used, wherein a color image is formed by yellow, magenta, and cyan dyes.
In order to form a cyan dye image out of these, conventionally, use is made of phenol- or naphthol-series couplers. Since the dyes formed from these couplers have, however, undesirable absorption in the region from yellow to magenta, they have a problem of making the color reproduction deteriorated, which is earnestly desired to be solved.
Particularly in recent years, the demand for so-called digital photographs has been increasing, wherein image information has been subjected to image processing by digitizing it, and it has then been exposed onto a silver halide color photographic light-sensitive material based on the information. In such a case, a silver halide color photographic light-sensitive material is desired wherein, particularly, dyes that will be formed are free from the above undesirable absorption and have a wide color reproduction range.
As a means for solving this problem, heterocyclic compounds described, for example, in U.S. Pat. No. 4,728,598, U.S. Pat. No. 4,873,183, and European patent application laid-open No. 0249453 A2 are proposed. These couplers, however, have such fatal defects as that the coupling activity is low and the fastness of the dye is poor.
As couplers that overcome these problems, pyrrolotriazole couplers described in U.S. Pat. No. 5,256,526 and European patent No. 0545300 are proposed. Although these couplers are excellent in hue of a formed dye and coupling activity, it is found that further improvement is required, because the color photographic light-sensitive material in which these couplers are used is not satisfactory in fastness of the formed dye image, and in particular fastness to light of the formed dye image is inferior to an image formed with a conventional phenol-series coupler.
Further, when the color-forming property and fastness to light of dye image are to be improved, sometimes there arises a problem of so-called cyan stain; that is, cyan color formation occurs in non-image areas.
As a means for improving fastness to light of the above pyrrolotriazole couplers, a method in which they are used in combination with phenol-series couplers is proposed in JP-A-9-288337 ("JP-A" means unexamined published Japanese patent application). However, not only do phenol-series couplers damage color reproduction as mentioned above, they also have the problem (referred to as so-called blix discoloration (blix fading)) that the color forming property is lowered by their change to leuco dyes (reduction and decoloring of part of the dyes) when bleach-fixing is carried out. Although JP-A-9-171240 describes that blix discoloration of cyan dyes is improved by means of a certain polymer, the conventional technique still cannot secure excellent color reproduction and satisfactory dye image fastness without deteriorating the processability; for example, without causing the blix discoloration.